Surabaya weather in January
In January, Surabaya has daytime highs averaging 29 °C, nights around 25 °C, with 29 wet days, and a sea temperature of 29 °C. Figures are 1991–2020 climate normals.
- 29.4°C Average high
- 24.8°C Average low
- 29days Wet days
- 285mm Rainfall
- 29.4°C Sea temperature
- 13h Daylight
Daily temperatures through January
How January develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 January | 29.5 °C | 24.9 °C | 92 % |
| 11–20 January | 29.5 °C | 24.8 °C | 93 % |
| 21–31 January | 29.2 °C | 24.8 °C | 97 % |
- Rain is most likely over days 21–31 of January (97 % of days) and least likely over days 1–10 (92 %).
What to expect
| Measure | Typical January | Share of the month |
|---|---|---|
| Days above 25 °C | 31 of 31 | 100 % |
| Days above 30 °C | 9.0 of 31 | 29 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 29 of 31 | 94 % |
Conditions in January
| Measure | Average |
|---|---|
| Mean temperature | 27 °C |
| Record high (1991–2020) | 33 °C |
| Record low (1991–2020) | 23 °C |
| Relative humidity | 85 % |
| Wind speed | 14 km/h |
| Cloud cover | 89 % |
Where Surabaya ranks in January
| Ranking | Position | Value |
|---|---|---|
| Warmest sea temperatures in Asia in January | 8thof 50 | 29 °C |
| Warmest sea temperatures in the world in January | 10thof 50 | 29 °C |
January compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 29.4 °C | 285 mm | 89 % |
| February | 29.4 °C | 263 mm | 90 % |
| March | 29.8 °C | 262 mm | 82 % |
| November | 31.4 °C | 176 mm | 77 % |
| December | 29.9 °C | 271 mm | 88 % |
See all twelve months for Surabaya
- January is the 11th warmest month here.
- It is the 12th driest month of the year.
- It ranks 11th for least cloud cover.
- Days last about 13 hours from sunrise to sunset.
- It rains on 29 of 31 days — 94 % of the month.
- Nights are about 4.6 °C cooler than the middle of the day.
- The hottest January day on record since 1991 reached 33 °C, 3.5 °C above the usual daytime high.
- Beach score: 67 / 100 — see how this is calculated.
Nearby destinations in January
| Destination | Avg high | Wet days | Sea |
|---|---|---|---|
| Surabaya | 29 °C | 29 | 29 |
| Pasuruan | 29 °C | 29 | 29 |
| Singosari | 27 °C | 29 | – |
| Batu | 26 °C | 29 | – |
| Probolinggo | 28 °C | 28 | 29 |
| Malang | 27 °C | 29 | – |
| Kediri | 29 °C | 29 | – |
| Blitar | 28 °C | 29 | – |
QuestionsJanuary in Surabaya, answered
How warm is Surabaya in January?
Daily highs average 29 °C and nights fall to about 25 °C, a spread of 4.6 °C between afternoon and dawn. That makes January the 11th warmest month of the year here.
Does it rain much in Surabaya in January?
January averages 285 mm of rain, spread over about 29 of the 31 days — 94 % of the month. Cloud cover averages 89 % of the sky.
Is the sea warm enough to swim in January?
The sea averages 29 °C off Surabaya in January. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in January?
Surabaya averages 13 hours between sunrise and sunset in January. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.